Differences in access to healthcare across different populations is the main reason for existing disparities in healthcare provision. These differences occur for several reasons and some of the main factors that contribute to the problem in the United States are described below.

• Lack of health insurance – Several racial, ethnic, socioeconomic and other minority groups lack adequate health insurance compared with the majority population. These individuals are more likely to delay healthcare and to go without the necessary healthcare or medication they should have been prescribed.
• Lack of financial resources – Lack of available finance is a barrier to healthcare for many Americans but access to healthcare is reduced most among minority populations. Racial and ethnic minorities are often given a health insurance plan that limits the amount of services available to them as well as the number of providers they can use.
• Irregular source of care – Compared to white individuals, ethnic or racial minorities are less likely to be able to visit the same doctor on a regular basis and tend to rely more on clinics and emergency rooms. Without a regular healthcare source, people have more difficulty obtaining their prescriptions and attending necessary appointments.
• Legal obstacles – Low-income immigrant groups are more likely to experience legal barriers. For example, insurance coverage through Medicaid is not available to immigrants who have been resident in the U.S for less than five years.
• Structural barriers – Examples of structural barriers include lack of transport to healthcare providers, inability to obtain convenient appointment times and lengthy waiting room times. All of these factors reduce the likelihood of a person successfully making and keeping their healthcare appointment.
• Lack of healthcare providers – In areas where minority populations are concentrated such as inner cities and rural areas, the number of health practitioners and diagnostic facilities is often inadequate.
• Language barriers – Poor English language skills can make it difficult for people to understand basic information about health conditions or when they should visit their doctor.
• Age – Older patients are often living on a fixed income and cannot afford to pay for their healthcare. Older people are also more likely to experience transport problems or suffer from a lack of mobility, factors that can impact on their access to healthcare. With 15% of the older adults in the U.S not having access to the internet, these individuals are also less likely to benefit form the valuable health information that can now be found on the internet.